The Arf6 GTP-binding protein has been shown to function at the plasma membrane to coordinate an endosomal membrane trafficking pathway and maintain the cortical actin cytoskeleton. We continue to follow functions for Arf6 as well as other Arf proteins at the cell surface and on endosomal membranes. We have also begun to examine functions of Arfs in other cells types in particular T cells. We continue to be interested in the issue of Arf proteins coordinating function with Rab proteins. In particular that Arf6 and Rab35 are antagonistic to each other in recruiting each other's GAPs. Thus activation of Arf6 leads to less activation of Rab35 and active Rab35 diminishes Arf6 activation. The cell uses this regulation to facilitate hand-off of cargo during endosomal trafficking.